build:staging npm script uses non-existent webpack.config.staging file

[lematt1991]

In package.json, perhaps

"build:staging": "NODE_ENV=development ./node_modules/.bin/webpack --progress --config webpack.config.staging",

should instead be:

"build:staging": "NODE_ENV=development ./node_modules/.bin/webpack --progress --config webpack.config.dev",

I'm currently getting

Error: Cannot find module '/Users/ml9951/repositories/context/webpack.config.staging'
    at Function.Module._resolveFilename (module.js:470:15)
    at Function.Module._load (module.js:418:25)
    at Module.require (module.js:498:17)
    at require (internal/module.js:20:19)

When I run npm run build:staging